Perfectionism, which the author defines as beliefs and behaviors associated with high expectations for one's performance, is not necessarily detrimental. Many successful people demonstrate perfectionism that the author labels "functional." They set goals that are attainable, based on realistic self-knowledge. When planning a new venture they focus on their strengths, and they react to challenges with excitement and a positive emotional charge. On the other hand, over the last 20 years the author has seen increasing numbers of gifted learners who set goals so high that they are impossible to reach or so low that achieving them is nearly guaranteed. When starting a new project they focus on their weaknesses and attempt to avoid doing anything wrong. They react to challenges with anxiety and confusion, and they become emotionally drained. "Dysfunctional perfectionists" are the students who put off starting tasks and then hibernate to complete their work. They are self-critical, even of their successes, and they have trouble focusing when challenging new content or ideas are introduced. They rarely ask for assistance, or they lasso parents into doing much of their work. Understanding the roots of dysfunctional perfectionism and some of the ways in which they play out in thinking and acting that derails gifted children and teens is only the beginning. Parents and teachers can help youngsters take charge of perfectionism, instead of being its victims, by using the methods presented in this article. (Contains 1 table.)